Maternal Vaccination as an Essential Component of Life-Course Immunization and Its Contribution to Preventive Neonatology

Factors associated with pregnant women's willingness to receive maternal pertussis vaccination in Guizhou Province, China: An exploratory cross-sectional study

The rise in pertussis incidence among infants in Guizhou, China underscores the need for maternal acellular pertussis vaccine (aP) immunization, a key strategy in protecting infants from severe health consequences. However, the willingness of pregnant women in Guizhou to receive this vaccine is not well-understood. This study aimed to explore pregnant women's intentions toward maternal pertussis vaccination in Guizhou and identify the associated factors. A questionnaire based on the health belief model, was administered in an exploratory cross-sectional study from January to February 2022. Data from 564 participants were collected and analyzed. The chi-square test, Mann-Whitney U test, and Poisson regression were used to identify potential factors associated with vaccination intentions. Participants' median age was 27 y (interquartile range (IQR): 24-31), and the median number of children per participant was one. The study found that only 36.0% of the participants intended to receive the aP vaccine while 64.0% were uncertain or negative in this regard. Significant factors associated with intentions to vaccinate included perceived barriers and cues for action and perceived benefits. The major barriers for low vaccination intentions were safety concerns for both the fetus and the mother, and family members' negative attitudes. Free vaccines, perceiving preventive benefits, observing other pregnant women getting vaccinated, and healthcare provider recommendations may facilitate vaccination intentions. Multiple immune strategies should be developed or optimized to cope with the resurgence of pertussis.

Comparison of Wealth-Related Inequality in Tetanus Vaccination Coverage before and during Pregnancy: A Cross-Sectional Analysis of 72 Low- and Middle-Income Countries

Immunization of pregnant women against tetanus is a key strategy for reducing tetanus morbidity and mortality while also achieving the goal of maternal and neonatal tetanus elimination. Despite substantial progress in improving newborn protection from tetanus at birth through maternal immunization, umbilical cord practices and sterilized and safe deliveries, inequitable gaps in protection remain. Notably, an infant's tetanus protection at birth is comprised of immunization received by the mother during and before the pregnancy (e.g., through childhood vaccination, booster doses, mass vaccination campaigns, or during prior pregnancies). In this work, we examine wealth-related inequalities in maternal tetanus toxoid containing vaccination coverage before pregnancy, during pregnancy, and at birth for 72 low- and middle-income countries with a recent Demographic and Health Survey or Multiple Indicator Cluster Survey (between 2013 and 2022). We summarize coverage levels and absolute and relative inequalities at each time point; compare the relative contributions of inequalities before and during pregnancy to inequalities at birth; and examine associations between inequalities and coverage levels. We present the findings for countries individually and on aggregate, by World Bank country income grouping, as well as by maternal and neonatal tetanus elimination status, finding that most of the inequality in tetanus immunization coverage at birth is introduced during pregnancy. Inequalities in coverage during pregnancy are most pronounced in low- and lower-middle-income countries, and even more so in countries which have not achieved maternal and neonatal tetanus elimination. These findings suggest that pregnancy is a key time of opportunity for equity-oriented interventions to improve maternal tetanus immunization coverage.

Vaccination: Adherence and Hesitancy among Pregnant Women for COVID-19, Pertussis, and Influenza Vaccines

In the realm of antenatal care, vaccinations serve as a cornerstone, crucial for safeguarding the health of both the mother and the fetus, while also extending protection to the newborn against communicable diseases. Nevertheless, vaccine adherence among pregnant women remains very low. The aim of our study was to evaluate the uptake of vaccines (influence, pertussis, and COVID-19) among women during pregnancy and to understand pregnant women's knowledge of vaccines and the diseases they protect against. The purpose was to investigate the reasons why pregnant women chose not to be vaccinated and to develop effective strategies for informing them about the importance of vaccination for both maternal and fetal safety. A prospective observational study was conducted in the Department of Obstetrics and Gynaecology, "Ospedale Santa Maria della Misericordia" in Udine, from 1 December 2021 to 30 June 2022. During this period, a self-completed paper questionnaire was administered to women at the end of pregnancy or during the puerperium. A total of 161 questionnaires were collected. Higher educational level was found to be significantly associated with influenza vaccination uptake (p = 0.037, OR = 2.18, 95% CI 1.05-4.51). Similarly, for pertussis vaccination, adherence was mainly associated with higher educational level (p = 0.014, OR = 2.83, 95% CI 1.24-6.47), but also with Italian nationality (p = 0.003, OR = 3.36, 95% CI 1.56-8.43) and pregnancy attended by a midwife or private gynecologist (p = 0.028, OR = 0.39, 95% CI 0.17-0.90). Regarding the COVID-19 vaccine, the only factor positively influencing uptake was Italian nationality (p = 0.044, OR = 2.66, 95% CI 1.03-6.91). Women's fear that vaccines would endanger the fetus appeared to be the most important reason for refusing vaccinations. Simultaneously, patients also exhibited a desire to receive more information about maternal vaccination, particularly from their general physician or gynecologist. For this reason, it is imperative to enhance maternal vaccination counselling, making it a routine step in prenatal care from the first antenatal visit until the postpartum period.

Maternal awareness, acceptability and willingness towards respiratory syncytial virus (RSV) vaccination during pregnancy in Ireland

BACKGROUND

Respiratory syncytial virus (RSV) is the world's leading cause of viral acute lower respiratory infections (ALRI) in infants. WHO has identified maternal RSV vaccination a priority and candidate vaccines are in development; however, vaccine hesitancy remains an impediment to successful implementation of maternal immunization. This study, the largest antenatal survey conducted to-date, aimed to examine maternal RSV awareness, likely acceptance of RSV vaccination in pregnancy, and attitudes to maternal vaccination.

METHODS

Pregnant women of all gestations attending antenatal clinic of a university maternity hospital in Ireland were invited to participate. An information leaflet provided, consent obtained, and survey administered examining RSV awareness, willingness to avail of antenatal RSV vaccination, factors influencing acceptability and preferred sources of assistance. Research Ethics Committee (REC) approval obtained, and general data protection regulation (GDPR) guidelines followed.

RESULTS

528 women completed the survey. A large proportion (75.6%) had never heard of RSV, yet 48.5% would still avail of a vaccine, 45.8% were undecided and only 5.3% would not. The main factor making vaccination acceptable to women (76.4%) was that it protects their infant from illness (p < .001, CV 0.336 for association with acceptance) and general practitioner (GP) was the preferred guidance source in decision-making (57.7%).

CONCLUSIONS

Despite low levels of maternal awareness of RSV, pregnant women in Ireland are open to availing of antenatal vaccination. Maternal immunization strategies need to focus on infant's protection from RSV-associated ALRI along with vaccine safety, and build on an interdisciplinary collaboration of maternal, neonatal, primary care and public health services.

Are maternal vaccines effective and safe for mothers and infants? A systematic review and meta-analysis of randomised controlled trials

INTRODUCTION

Maternal vaccination is a promising strategy to reduce the burden of vaccine-preventable diseases for mothers and infants. We aimed to provide an up-to-date overview of the efficacy and safety of all available maternal vaccines.

METHODS

We searched PubMed, Embase, CENTRAL and ClinicalTrials.gov on 1 February 2022, for phase III and IV randomised controlled trials (RCTs) that compared maternal vaccination against any pathogen with placebo or no vaccination. Primary outcomes were laboratory-confirmed or clinically confirmed disease in mothers and infants. Secondary safety outcomes included intrauterine growth restriction, stillbirth, maternal death, preterm birth, congenital malformations and infant death. Random effects meta-analysis were used to calculate pooled risk ratio's (RR). Quality appraisal was performed using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE).

RESULTS

Six RCTs on four maternal vaccines, influenza, tetanus, diphtheria and pertussis (Tdap), pneumococcal and respiratory syncytial virus (RSV) were eligible. The overall risk of bias and certainty of evidence varied from low to high. Maternal influenza vaccination significantly reduced the number of laboratory-confirmed influenza cases (RR 0.58, 95% CI 0.42 to 0.79, event rate 57 vs 98, 2 RCTs, n=6003, I2=0%), and clinically confirmed influenza cases in mothers (RR 0.88, 95% CI 0.78 to 0.99, event rate 418 vs 472, 2 RCTs, n=6003, I2=0%), and laboratory-confirmed influenza in infants (RR 0.66, 95% CI 0.52 to 0.85, event rate 98 vs 148, 2 RCTs, n=5883, I2=0%), although this was not significant for clinically confirmed influenza in infants (RR 0.99, 95% CI 0.94 to 1.05, event rate 1371 vs 1378, 2 RCTs, n=5883, I2=0%). No efficacy data were available on maternal Tdap vaccination. Maternal pneumococcal vaccination did not reduce laboratory-confirmed and clinically confirmed middle ear disease (RR 0.49, 95% CI 0.24 to 1.02, event rate 9 vs 18, 1 RCT, n=133 and RR 0.88 95% CI 0.69 to 1.12, event rate 42 vs 47, 1 RCT, n=133, respectively), and clinically confirmed lower-respiratory tract infection (LRTI) (RR 1.08, 95% CI 0.82 to 1.43, event rate 18 vs 34, 1 RCT, n=70) in infants. Maternal RSV vaccination did not reduce laboratory-confirmed RSV LRTI in infants (RR 0.75, 95% CI 0.56 to 1.01, event rate 103 vs 71, 1 RCT, n=4527). There was no evidence of a significant effect of any of the maternal vaccines on the reported safety outcomes.

CONCLUSIONS

The few RCTs with low event rates suggest that, depending on the type of maternal vaccine, the vaccine might effectively prevent disease and within its size does not show safety concerns in mothers and infants.

PROSPERO REGISTRATION NUMBER

CRD42021235115.

Sources of COVID-19 Vaccine Promotion for Pregnant and Lactating Women in Bangladesh

COVID-19 vaccines are an effective public health intervention to reduce COVID-19-related morbidity and mortality. Given that pregnant and lactating women have a higher risk of severe COVID-19 complications, it is paramount to understand the factors that inform vaccine decision-making among this population. In this study, we sought to identify facilitators and barriers to COVID-19 vaccine acceptance and vaccine promotion in pregnant and lactating women in Bangladesh. We conducted 40 in-depth interviews with 12 pregnant women, 12 lactating women, and 16 health workers from one urban and four rural communities in Bangladesh. We used a grounded theory approach to identify emerging themes. Our results suggest that health workers and religious leaders played key roles in promoting COVID-19 vaccines in this population. Further, we found that the culture of trust in public health authorities and the existing vaccine infrastructure facilitated vaccine promotion. However, changes in vaccine eligibility and myths and rumors acted as both facilitators and barriers to vaccine promotion within our study. It is crucial that maternal immunization vaccine promotion efforts push pregnant and lactating women toward vaccine acceptance to protect the health of mothers and their babies. Additionally, as new maternal vaccines are developed and licensed, understanding how to best promote vaccines within this group is paramount.

Impact of breastfeeding on the incidence and severity of respiratory syncytial virus (RSV)-associated acute lower respiratory infections in infants: a systematic review highlighting the global relevance of primary prevention

BACKGROUND

Respiratory syncytial virus (RSV) is the principal cause of acute lower respiratory infections (ALRI) among infants worldwide, and an important cause of morbidity, hospitalisation and mortality. While infants are universally exposed to RSV, most mortality occurs among normal term infants from low-income and middle-income countries. Breastfeeding has been suggested to have a protective effect against RSV infection. This study aims to determine the association of breastfeeding on the frequency and severity of RSV-associated ALRI among infants.

METHODS

A systematic review was conducted using keywords and Medical Subject Headings on MEDLINE, PubMed, Google Scholar, EMBASE, MedRxiv and Cochrane Central Register of Controlled Trials. Full-text articles published in English from 2000 to 2021 that studied exclusively or partially breastfed infants who developed RSV-associated ALRI <12 months of age were included. Covidence software-based evidence extraction and Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocol guidelines were followed. Quality of evidence was analysed using UK National Service Framework grading and the risk-of-bias assessment using Robvis.

RESULTS

Among 1368 studies screened, 217 qualified full-text review and 198 were excluded based on pre-agreed criteria. Nineteen articles published from 12 countries that included 16 787 infants from 31 countries (of which 8 middle-income) were retained for analysis. Results indicate that non-breastfeeding practices pose a significant risk for severe RSV-associated ALRI and hospitalisation. Exclusive breastfeeding for >4-6 months significantly lowered hospitalisation, length of stay, supplemental oxygen demand and admission to intensive care units.

CONCLUSION

In the context of no effective or standardised treatment for established RSV-associated ALRI, available evidence suggest that breastfeeding is associated with lower frequency and severity of RSV-associated ALRI, based on observational studies of variable grades of evidence and risk-of-bias. With both exclusive and partial breastfeeding benefiting infants who develop RSV-associated ALRI, breastfeeding should be promoted globally as an adjunct primary prevention; in addition to emerging immunoprophylaxis and maternal immunisation strategies.

Preventing invasive meningococcal disease in early infancy

This review considers the pathogenesis, diagnosis, and epidemiology of invasive meningococcal disease in infants, to examine and critique meningococcal disease prevention in this population through vaccination. High rates of meningococcal disease and poor outcomes, particularly for very young infants, highlight the importance of meningococcal vaccination in early infancy. Although effective and safe meningococcal vaccines are available for use from 6 weeks of age, they are not recommended globally. Emerging real-world data from the increased incorporation of these vaccines within immunization programs inform recommendations regarding effectiveness, appropriate vaccination schedule, possible long-term safety effects, and persistence of antibody responses. Importantly, to protect infants from IMD, national vaccination recommendations should be consistent with available data regarding vaccine safety, effectiveness, and disease risk.

'My primary purpose is to protect the unborn child': Understanding pregnant women's perceptions of maternal vaccination and vaccine trials in Europe

Despite the important benefits of maternal vaccination for pregnant women and newborns, vaccination uptake is low in many European countries. Differences in vaccination policies and recommendations, as well as concerns about vaccine safety can partly explain inadequate coverage rates and women's hesitancy to get vaccinated during pregnancy. This study aims to explore pregnant women's experiences, decision-making processes and perceptions towards maternal vaccination and maternal vaccine trials in France, Germany, Italy, Spain and the United Kingdom. Qualitative interviews and focus groups were conducted with 258 pregnant women identified through local research panels and snowballing. Topic guides translated in local languages were designed to explore women's awareness and perceptions of maternal vaccination, and willingness to participate in vaccine trials during pregnancy. A thematic analysis was conducted. Pregnant women were found to have low awareness about maternal vaccination, with many reporting not having received a recommendation to vaccinate from their doctors. Strong trust in health professionals indicate that strengthened recommendations could improve vaccination uptake. Vaccination decision-making in pregnancy was described in the context of a highly emotional period, generating anxiety and fears around the safety of vaccines. Pregnancy was also discussed as a period during which women develop nurturing and protective identities. However, depending on the information they received as well as influences from experts, families and peers, women either perceived vaccination as a threat to their babies' safety or as a means to protect them. Attitudes towards maternal vaccine trials were less ambiguous, with most pregnant women strongly rejecting the notion of taking part in trials. While strategies to improve pregnant women's awareness and perceptions of maternal vaccination are needed, it is equally important to understand why healthcare professionals may not be recommending vaccination. More coordinated strategies across Europe could help strengthen communication and trust in maternal vaccination.

Altruism and vaccination intentions: Evidence from behavioral experiments

Vaccine hesitancy has been on the rise throughout the past two decades, especially in high income countries where existing pro-vaccination public health communication strategies have proven ineffective. We argue that appealing to other-regarding preferences is one way of improving the effectiveness of public health communication strategies. To test this argument, we assess how vaccination intentions are influenced by the presence of people who cannot vaccinate, such as the immunosuppressed, newborns or pregnant women, using a laboratory experiment where there is a passive player whose welfare depends on the decisions of other, active players. Results suggest that pro-vaccine messages targeting altruism can increase vaccination intentions by: (i) invoking past experiences of dependence and vulnerability; (ii) stressing cooperation as a social norm; and (iii) emphasizing the presence of vulnerable individuals in a given society.

"From my phone, I could rule the world": Critical engagement with maternal vaccine information, vaccine confidence builders and post-Zika outbreak rumours in Brazil

Maternal immunization is key to protecting maternal and newborn health. We interviewed pregnant women in Brazil to identify barriers to and enablers of maternal immunization in the country. In-depth interviews and focus groups were conducted in Brazil with 60 pregnant women from São Paulo and Rio de Janeiro at different stages of their pregnancies. Participants were encouraged to discuss views on safety, efficacy and importance of maternal vaccines, access to vaccines, interactions with healthcare professionals, and sources of information on vaccine-related matters. There was generally a positive regard for maternal immunization among the interviewed women, many of whom associated vaccination with protection of their unborn child. The interviewees cited several reasons for adherence to immunization guidelines, including recommendations from healthcare professionals, targeted communication campaigns, and active use of a vaccination card or booklet. There were no reported barriers for maternal vaccines. Some women using private healthcare services reported not having been asked about vaccines at check-ups, which could adversely affect vaccination rates. A rumour that vaccines caused microcephaly which emerged during the Zika outbreak was the most commonly cited reason for choosing not to vaccinate among the interviewees. This study identified important vaccine confidence builders. Many of the interviewees critically reflected upon information received, placing themselves as the decision makers over their health choices. A prominent barrier to maternal immunization was a rumour linking vaccines to microcephaly. To the best of our knowledge, this has not been previously reported in the literature and requires further investigation into the extent of this issue and how it can be mitigated.

Trust, emotions and risks: Pregnant women's perceptions, confidence and decision-making practices around maternal vaccination in France

Maternal vaccination is an important strategy to reduce maternal and newborn mortality and morbidity. Yet, vaccination uptake is suboptimal in many countries, including France. This mixed-method study aimed to identify factors influencing maternal vaccination, exploring pregnant women's perceptions, confidence, and decision-making processes in France. Maternal vaccination uptake was positively associated with awareness of maternal vaccines, confidence in vaccine effectiveness and receiving a recommendation from a healthcare professional. A trusting relationship with healthcare professionals was observed as crucial for women during pregnancy. Even if women considered themselves as sole decision-makers, healthcare professionals' role in decision-making was viewed as substantial. Pregnancy can be a complex time for assessing risks, which was evident in the strong emotional reactions to maternal vaccination and anxieties about safety. As new maternal vaccines are developed, it is crucial to consider women's values, risk perceptions and emotions in the development of strategies to support acceptance of maternal vaccination.

Methodologic approaches in studies using real-world data (RWD) to measure pediatric safety and effectiveness of vaccines administered to pregnant women: A scoping review

OBJECTIVE

This scoping review mapped studies using real-world data (RWD) to measure pediatric safety and effectiveness of vaccines administered to pregnant women.

INTRODUCTION

In the US, two vaccines are recommended for all pregnant women to prevent illness in the infant: inactivated influenza vaccine (recommended since 2004), and the combined tetanus-diphtheria-acellular pertussis (Tdap) vaccine (recommended since 2013). This scoping review maps the studies conducted to date that address questions about pediatric safety and effectiveness of vaccines administered during pregnancy and provides a knowledge base for evaluating the use of RWD to study this issue.

METHODS

The scoping review was conducted following a published protocol. Methods included an electronic search of PubMed and Embase, screening of titles and abstracts by two reviewers, and double extraction of data for summary and synthesis. Studies that reported on pregnant women and the effectiveness or safety outcomes in their infants were included.

RESULTS

Forty-eight studies met the inclusion criteria of the scoping review protocol using RWD to assess safety or effectiveness of influenza or pertussis vaccinations administered to pregnant women with respect to pregnancy, infant or child outcomes. Detailed information about data sources, linkage of maternal and infant data, and operational definitions for gestational age were largely absent from the majority of studies raising concerns about reproducibility and validity of study findings.

CONCLUSIONS

A body of literature is available from which to plan and design future studies of vaccination in pregnant women using RWD. This is of intense importance as new vaccines, such as those for COVID-19, become available to the general population via approval or authorization without inclusion of pregnant women in the clinical trials.

Maternal Vaccination in Uganda: Exploring Pregnant Women, Community Leaders and Healthcare Workers' Perceptions

Background: We investigated pregnant women, community leaders, healthcare workers (HCWs) and programme managers' perceptions of maternal vaccination in Kampala, Uganda. Methods: We conducted focus group discussions, key informant interviews and in-depth discussions with HCWs (3), community leaders (3), pregnant women (8) and programme managers (10) between November 2019 and October 2020. Data were analysed thematically. Results: Pregnant women, community leaders and some HCWs had limited maternal immunisation knowledge. There was confusion over what constitutes a vaccine. Pregnant women may not receive vaccines because of mistrust of government; use of expired vaccines; reliance on traditional medicine; religious beliefs; fear of side effects; HCWs attitudes; and logistical issues. The key facilitators of maternal vaccination were a desire to prevent diseases, positive influences from HCWs and information about vaccine side effects. Community leaders and some pregnant women highlighted that pregnant women do not make decisions about maternal vaccination independently and are influenced by different individuals, including other pregnant women, older people, partners, relatives (parents), community leaders, HCWs and the government. Conclusions: Our results indicate that public health messaging should target all community members, including partners and parents of pregnant women as well as HCWs, to improve knowledge of and confidence in maternal vaccines.

β-Lactoglobulin and Glycodelin: Two Sides of the Same Coin?

The two lipocalins, β-lactoglobulin (βLg) and glycodelin (Gd), are possibly the most closely related members of the large and widely distributed lipocalin family, yet their functions appear to be substantially different. Indeed, the function of β-lactoglobulin, a major component of ruminant milk, is still unclear although neonatal nutrition is clearly important. On the other hand, glycodelin has several specific functions in reproduction conferred through distinct, tissue specific glycosylation of the polypeptide backbone. It is also associated with some cancer outcomes. The glycodelin gene, PAEP, reflecting one of its names, progestagen-associated endometrial protein, is expressed in many though not all primates, but the name has now also been adopted for the β-lactoglobulin gene (HGNC, www.genenames.org). After a general overview of the two proteins in the context of the lipocalin family, this review considers the properties of each in the light of their physiological functional significance, supplementing earlier reviews to include studies from the past decade. While the biological function of glycodelin is reasonably well defined, that of β-lactoglobulin remains elusive.

Methodologic approaches in studies using real-world data to measure pediatric safety and effectiveness of vaccines administered to pregnant women: a scoping review protocol

OBJECTIVE

This scoping review aims to map studies using real-world data (RWD) to measure pediatric safety and effectiveness of vaccines administered to pregnant women.

INTRODUCTION

In the United States, two vaccines are recommended for all pregnant women to prevent illness in the infant: inactivated influenza vaccine (recommended since 2004) and the combined tetanus-diphtheria-acellular pertussis (Tdap) vaccine (recommended since 2013). Because of the ethical constraints in conducting randomized clinical trials to measure the effects on the infant, there is great interest in using electronic health care data or administrative claims data to study the effects of maternal immunization on the infant's health, and it is anticipated that such studies may be submitted to support regulatory decision-making. This scoping review will map the studies conducted to date that address these questions and provide a context for considering the regulatory issues that may arise in the future.

INCLUSION CRITERIA

Studies that report on pregnant women receiving immunization and the effectiveness or safety outcomes in their infants will be included. Study participants may be from any population or country, of any reproductive age, and with any health status. Studies will be included if they use real-world data (from electronic health records, administrative claims, pharmacy benefit records, or registries).

METHODS

An electronic search of PubMed and Embase will identify citations for screening. The search will be limited to studies published in English during the preceding 10 years. Two reviewers will screen citations in a two-step process (titles and abstracts, then full-text articles), and two reviewers will extract data for summary and synthesis.

Vaccination in preterm and low birth weight infants in India

In India, the high neonatal and infant mortality rate is due in part to an increasing number of preterm and low birth weight (LBW) infants. Given the immaturity of immune system, these infants are at an increased risk of hospitalization and mortality from vaccine-preventable diseases (VPDs). In this narrative review, we screened the scientific literature for data on the risk of VPDs, vaccination delay and factors related to it in Indian preterm and LBW infants. Although routine childhood vaccinations are recommended regardless of gestational age or birth weight, vaccination is often delayed. It exposes these infants to a higher risk of infections, their associated complications, and death. After-birth complications, lack of awareness of recommendations, vaccine efficacy and effectiveness and concerns related to safety are some of the common barriers to vaccination. Awareness campaigns might help substantiate the need for (and value of) vaccination in preterm and LBW infants.

What is the context?

In India, the high neonatal mortality rate is due in part to an increasing number of pretern and low birth weight intants.

Affected infants have a poorly developed inmune system and are more susceptible to contracting vaccine-preventable diseases.

The Indian Academy of Pediatrics recommends vaccination according to the same schedule used for full term infants, following chronological (not gestational) age.

Delays in vaccinations increase the risk of preventable infections.

What is new?

Our review of the scientific literature shows that, in India:

infections have more serious conseuences in preterm and low birth weight infants

delays to vaccinate affected infants are common, mostly due to safety and effectiveness concerns from parents and healthcare pracitionrs.

What is the impact?

Improving mternal nutritional status and immunization, and perinatal care could help reduce the number of preterm and low birth weight infants.

Combining maternal immunization with vaccination of affected infants can confer safe and effective protection.

Awareness campaigns for parents and healthcare practitioners could address the issue of vaccination delay in pretern and low birth weight infants in India.

The Protective Role of Maternal Immunization in Early Life

With birth, the newborn is transferred from a quasi-sterile environment to the outside world. At this time, the neonatal immune system is inexperienced and continuously subject to a process of development as it encounters different antigenic stimuli after birth. It is initially characterized by a bias toward T helper 2 phenotype, reduced T helper 1, and cytotoxic responses to microbial stimuli, low levels of memory, and effector T and B cells and a high production of suppressive T regulatory cells. The aim of this setting, during fetal life, is to maintain an anti-inflammatory state and immune-tolerance. Maternal antibodies are transferred during pregnancy through the placenta and, in the first weeks of life of the newborn, they represent a powerful tool for protection. Thus, optimization of vaccination in pregnancy represents an important strategy to reduce the burden of neonatal infections and sepsis. Beneficial effects of maternal immunization are universally recognized, although the optimal timing of vaccination in pregnancy remains to be defined. Interestingly, the dynamic exchange that takes place at the fetal-maternal interface allows the transfer not only of antibodies, but also of maternal antigen presenting cells, probably in order to stimulate the developing fetal immune system in a harmless way. There are still controversial effects related to maternal immunization including the so called "immunology blunting," i.e., a dampened antibody production following infant's vaccination in those infants who received placentally transferred maternal immunity. However, clinical relevance of this phenomenon is still not clear. This review will provide an overview of the evolution of the immune system in early life and discuss the benefits of maternal vaccination. Current maternal vaccination policies and their rationale will be summarized on the road to promising approaches to enhance immunity in the neonate.

Determinants of policy and uptake of national vaccine programs for pregnant women: results of mixed method study from Spain, Italy, and India

An important strategy for addressing maternal and newborn risks of disease is through vaccinating pregnant women. We conducted a mixed-methods study including a narrative literature review of drivers of maternal vaccination and key informant interviews in Spain, Italy, and India to characterize different approaches to national maternal immunization programs. Fifty-nine respondents participated in the study conducted between November 2018 and January 2019. Policies in Spain and Italy both reflect a life-course approach to vaccination, but recommendations and how they ensure uptake differs. Italy was focused on tracking of progress and mandates to ensure compliance in all regions, while Spain, an early adopter, relied more on advocacy and building provider acceptance. India includes Td in their national program, but the political will and advocacy for other vaccines are not seen. Needs for improving rates of maternal vaccination include education of health-care providers and pregnant women, use of central registries to track progress, stronger global guidance for use of vaccines, and engagement of champions, particularly obstetrician-gynecologists (ob-gyns). Health security concerns can also be leveraged to build political priority and needed platforms to detect disease and deliver vaccines in some countries. Understanding what drives a country’s maternal immunization program decisions and the success of implementation is useful in designing strategies to share best practices and guide support to strengthen platforms for maternal vaccination.

Health Care Professionals' Perspectives on Life-Course Immunization: A Qualitative Survey from a European Conference

Today, fewer children die each year from vaccine-preventable diseases than older adults. Health systems need new immunization strategies to tackle the burden of vaccine-preventable disease in an aging society. A life-course immunization (LCI) approach-which entails vaccination throughout an individual's lifespan-enables adults to age with reduced risk to disease, thereby enabling healthy, active and productive aging. We conducted an audience response system (ARS)-based survey to investigate HCP perspectives on LCI in an opportunistic sample of 222 health care professionals (HCPs) from around the world who attended a European infectious diseases conference. Survey results show that LCI is a priority for HCPs (77.4%-88.6%), with most of them stating the need to frame it as a part of a healthy lifestyle (91.0%-100.0%). Insufficient LCI recommendations by vaccine providers (12.9%-33.3%) and governments (15.2%-41.9%) and insufficient targeted budget allocation (6.1%-21.7%) were indicated as the main barriers to implement LCI, ahead of vaccine hesitancy (9.7%-15.2%). HCPs were willing to make LCI a gateway to healthy aging but need support to work together with other stakeholders involved in the vaccination journey. This could be a step towards equitable health care for all of society.

Vaccination during pregnancy: current and possible future recommendations

Immunizing pregnant women to protect the mother, fetus and infant from infection has increasingly been used over the last decade. Protection against infectious diseases in neonates is mainly provided by maternal antibodies transferred from mother to infant during pregnancy through transplacental transport or after delivery via breastfeeding. Both the transplacental- and breast milk-derived maternal antibodies function as the primary source of protection against infectious diseases in neonates during the first vulnerable weeks of life. During recent infectious disease outbreaks (influenza, pertussis, Zika…) and for other infectious diseases (CMV, GBS…), pregnant women are increasingly identified as an important target for vaccination. For some of these diseases, vaccines are already on the market, and recommended during pregnancy. For others, vaccines are currently under development; furthermore, some are even specifically designed to be administered during pregnancy.Conclusion: This review article provides an overview on the rationale and main mechanism of the maternal vaccination strategy and gives a summary about the current and possible future recommendations for maternal vaccination.What is Known:• Maternal vaccination has a far-reaching potential in the protection of both women and offspring.• Currently, tetanus, pertussis and influenza vaccination during pregnancy is recommended in some countries. Several new vaccines specifically designed for use in pregnancy are currently under development.What is New:• Review providing a timely overview of the rationale and main mechanisms of the maternal vaccination strategy• Up-to-date summary of the current and possible future recommendations for maternal vaccination.

Closer and closer? Maternal immunization: current promise, future horizons

This state-of-the art manuscript highlights our current understanding of maternal immunization-the practice of vaccinating pregnant women to confer protection on them as well as on their young infants, and thereby reduce vaccine-preventable morbidity and mortality. Advances in our understanding of the immunologic processes that undergird a normal pregnancy, studies from vaccines currently available and recommended for pregnant women, and vaccines for administration in special situations are beginning to build the case for safe scale-up of maternal immunization. In addition to well-known diseases, new diseases are emerging which pose threats. Several new vaccines are currently under development and increasingly include pregnant women. In this manuscript, targeted at clinicians, vaccinologists, scientists, public health practitioners, and policymakers, we also outline key considerations around maternal immunization introduction and delivery, discuss noninfectious horizons for maternal immunization, and provide a framework for the clinician faced with immunizing a pregnant woman.

Breastfeeding and the Risk of Infant Illness in Asia: A Review

Infancy remains the most vulnerable period of human life for death, illness, and establishing a lifetime trajectory of growth and health. It is estimated that there are 5.3 million deaths under five years of age worldwide and approximately 800,000 lives could be saved by improving breastfeeding rates and duration. In Asia, an estimated 300,000-350,000 child deaths could be prevented with optimal breastfeeding and the majority would be under 12 months of age. We present a systematic review of studies of infection and breastfeeding in infants in Asia and further review interactions of selected infectious diseases and breastfeeding. Initially, 2459 records of possible interest were identified, 153 full text papers were reviewed in detail, and 13 papers describing diarrhoeal disease and/or acute respiratory tract infection were selected for inclusion in the review. Additional papers were selected to discuss specific diseases and their relationship to breastfeeding. The review found that a variety of methods were used with differing definitions of breastfeeding and diseases. Overall, breastfeeding when compared to the use of infant formula, is associated with significantly lower rates of diarrhoeal disease and lower respiratory tract infection, with a reduction of 50% or more to be expected, especially in infants under six months of age. The relationship between breastfeeding and specific diseases including measles and HTLV1 were reviewed. Breastfeeding reduces some disease rates, but there remain a few conditions where breastfeeding may be contra-indicated.

Human monoclonal antibodies for discovery, therapy, and vaccine acceleration

Screening of single B cells from convalescent or vaccinated people allows the discovery of novel targets for infectious diseases and rapid production of engineered human monoclonal antibodies (mAbs) that can prevent or control infections by passive immunization. Here we propose that the development of human mAbs can also significantly accelerate vaccine development by anticipating some of the key biological and regulatory questions.

Maternal interventions vigilance harmonization in low- and middle-income countries: Stakeholder meeting report; Amsterdam, May 1-2, 2018

Although major reductions in maternal and child mortality were achieved in the Millennium Development Goals era, progress must be accelerated to meet Sustainable Development Goals health targets by 2030. An estimated 2.7 million neonatal deaths and 2.6 million stillbirths still occur annually. Over the past several years there has been renewed global interest in innovative approaches to maternal immunization to potentially decrease mortality and severe morbidity in neonates, and in the pregnant woman and her fetus. Several new vaccines are in clinical development for indications in pregnant women, e.g., vaccines against respiratory syncytial virus, and group B streptococcus. Achieving near-concurrent introduction of new maternal vaccines in high-, middle-, and low-income countries requires that mechanisms are in place for appropriate safety monitoring worldwide.

The Bill & Melinda Gates Foundation convened a global expert meeting in Amsterdam on May 1–2, 2018, to discuss a framework for appropriate pharmacovigilance for vaccines used during pregnancy based on integrated maternal interventions vigilance (MIV) systems and collection of appropriate data to inform timely decision-making by and for pregnant women. Planning for MIV requires a multi-disciplinary, collaborative approach that fully leverages and builds upon existing resources, and builds new capabilities and capacity where needed. Meeting participants identified priority actions including (1) establishing background rates to better evaluate emerging safety signals and vaccine effectiveness, (2) identifying potential sentinel vaccine surveillance sites, (3) developing data sharing capabilities, (4) creating guidance documents and protocols, and (5) the advanced preparation of culturally-appropriate communication plans and risk management plans.

Integrating MIV across the routine obstetric and neonatal health care delivery continuum and all relevant programs and data systems could result in fundamental improvements in maternal, neonatal and child health. Improved pregnancy pharmacovigilance platforms may strengthen other vaccine and drug product safety systems and improve maternal and child research capabilities in LMICs.